package com.elong.util;

import java.security.MessageDigest;

public class MD5Util {

    /**
     * getMd5Str
      * @Title: getMd5Str
      * @Description: md5算法实现
      * @param str
      * @return
     */
    public static String getMd5Str(String str){
	MessageDigest digest = null;
	try {
	    digest = MessageDigest.getInstance("MD5");
	    digest.reset();
	    digest.update(str.getBytes("UTF-8"));
	} catch (Exception e) {
	    
	    System.exit(-1);
	}
	byte[] byteArray = digest.digest();
	
	StringBuffer md5StrBuff = new StringBuffer();
	
	for(int i = 0; i < byteArray.length; i++){
	    if(Integer.toHexString(0xFF & byteArray[i]).length() == 1){
		md5StrBuff.append("0").append(Integer.toHexString(0xFF & byteArray[i]));
	    }else{
		md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));
	    }
	}
	return md5StrBuff.toString();
    }
    
    public static void main(String[] args) {
	System.out.println(getMd5Str("aa"));
    }
    

}
